data(gorillas)
gorillas
is a marked point pattern (object
of class "ppp"
) representing nest site locations. gorillas.extra
is a named list of 7 pixel images (objects of
class "im"
) containing spatial covariates.
It also belongs to the class "listof"
. All spatial coordinates are in metres.
The coordinate reference system is WGS_84_UTM_Zone_32N
.vegetation
covariate is
also provided in the spatstat package installation,
as the file vegetation.asc
in the folder rawdata/gorillas
.
Use system.file
to obtain the file path:
system.file("rawdata/gorillas/vegetation.asc", package="spatstat")
.
This is a text file in the simple ASCII file format of the geospatial
library GDAL
. The file can be read by the function
readGDAL
in the rgdal package, or alternatively
read directly using scan
. The dataset gorillas
is a marked point pattern
(object of class "ppp"
)
giving the spatial locations of 647 nesting sites of gorilla groups
observed in the sanctuary over time.
Locations are given as UTM (Zone 32N) coordinates in metres.
The observation window is the boundary of the sanctuary, represented
as a polygon. Marks attached to the points are:
Note that the data contain duplicated points (two points at the
same location). To determine which points are duplicates,
use duplicated.ppp
.
To remove the duplication, use unique.ppp
.
The accompanying dataset gorillas.extra
contains
spatial covariate information. It is a named list containing
seven pixel images (objects of class "im"
) giving the values of
seven covariates over the study region. It also belongs
to the class "listof"
so that it can be plotted.
The component images are:
For further information see Funwi-Gabga and Mateu (2012).
Funwi-Gabga, N. and Mateu, J. (2012) Understanding the nesting spatial behaviour of gorillas in the Kagwene Sanctuary, Cameroon. Stochastic Environmental Research and Risk Assessment 26 (6), 793--811.
summary(gorillas)
plot(gorillas)
plot(gorillas.extra)
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